DNSSpoofing

DNS spoofing is the manipulation of the Domain Name System to deceive a user or a resolver into accepting a false IP address for a domain. By delivering forged DNS data, an attacker can cause a query for a legitimate domain to resolve to a malicious server, potentially enabling traffic interception, credential theft, or malware distribution. Spoofing exploits weaknesses in how DNS responses are matched to queries and can occur at various points in the resolution path.

Attack methods include cache poisoning, where forged responses are inserted into a resolver’s cache so subsequent queries return the attacker’s address. Historically, DNS spoofing relied on predicting the query/response pair; modern defenses aim to minimize this risk. Other modalities include man-in-the-middle positions, compromised routers or hosts that alter DNS settings, and rogue or misconfigured DNS servers that provide incorrect mappings. Pharming combines DNS manipulation with client-side or network-level redirection to achieve similar outcomes.

The impact of DNS spoofing can be severe, enabling phishing, redirection to counterfeit sites, credential theft, drive-by malware installation, or surveillance of user activity. Preventive measures focus on both protocol-level defenses and network hygiene. DNSSEC provides cryptographic authentication of DNS data, reducing the likelihood that forged responses are trusted. Adoption of DNSSEC validation, DNS over TLS or DNS over HTTPS to encrypt queries, and careful server configuration help mitigate spoofing. Additional defenses include source port randomization, query ID entropy, ingress filtering, and operating secure resolver infrastructure. Ongoing monitoring for unexpected DNS results aids detection and response.